从 xml 元素中选择属性

我试图从我的根节点中选择一个属性，但我在选择部分上不断收到空异常。

获取属性值的正确方法是什么？

我试图获取属性值的值：SymbolicName

xml文档：

<Bundle xmlns="urn:uiosp-bundle-manifest-2.0" Name="ContactUsPlugin" SymbolicName="ContactUsPlugin" Version="1" InitializedState="Active">
  <Activator Type="ContactUsPlugin.Activator" Policy="Immediate" />
  <Runtime>
    <Assembly Path="bin\ContactUsPlugin.dll" Share="false" />
  </Runtime>

  <Functionality>
    <Controller>About</Controller>
    <View>Index</View>
  </Functionality>

  <Scripts>
    <Script version="1">
      <Location>E:\Git Projects\Kapsters\Plugins\ContactUsPlugin\Sql\Sql1.txt</Location>
    </Script>
    <Script version="2">
      <Location>E:\Git Projects\Kapsters\Plugins\ContactUsPlugin\Sql\Sql1.txt</Location>
    </Script>
  </Scripts>
</Bundle>

I tried:

  string widgetCodeName =
            (from db in ManifestDocument.Elements() select db.Attribute("SymbolicName").Value).First();

   string widgetCodeName =
            (from db in ManifestDocument.Descendants() select db.Element("Bundle").Attribute("SymbolicName").Value).First();

  string widgetCodeName =
            (from db in ManifestDocument.Element("Bundle").Attributes() where db.Name == "SymbolicName" select db.Value).First();

根据您拥有的 xml，bundle 标签是根节点。尝试：

string widgetCodeName = ManifestDocument.Root.Attribute("SymbolicName").Value;